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They really are very variable in size. Often they are no bigger than a large Syrphus, but sometimes you fing huge ones...I saw one this morning which would challenge the larger horseflies for Britain's bulkiest fly, I should think.
My Flickr photos...
All I can say in response is, I wouldn't like to be bitten by the horsefly that's bigger than one of these. Then again, I havent seen the horseflies you are refering to. Any of these Ive seen have been pretty chunky insects.
How big are your local horseflies??? (Different shape I know)
Have a look at pics of Tabanus sudeticus. About the size of a small dog...but fortunately they don't bite man!
I see what you mean now Ian, that's big! It looks like a hawkmoth species. Yes it's a good job they don't bite humans. Thanks for the link.
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